
export const dialogDrag = {
    install(Vue) {
        Vue.directive('dialogDrag', {
            bind(el, binding, vnode, oldVnode) {

                //弹框可拉伸最小宽高

                let minWidth = 400;

                let minHeight = 300;

                //初始非全屏

                let isFullScreen = false;

                //当前宽高

                let nowWidth = 0;

                let nowHight = 0;

                //当前顶部高度

                let nowMarginTop = 0;

                //获取弹框头部（这部分可双击全屏）

                const dialogHeaderEl = el.querySelector('.el-dialog__header');

                //弹窗

                const dragDom = el.querySelector('.el-dialog');

                //给弹窗加上overflow auto；不然缩小时框内的标签可能超出dialog；

                dragDom.style.overflow = "auto";

                //清除选择头部文字效果

                //dialogHeaderEl.onselectstart = new Function("return false");

                //头部加上可拖动cursor

                dialogHeaderEl.style.cursor = 'move';

                // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);

                const sty = dragDom.currentStyle || window.getComputedStyle(dragDom, null);

                let moveDown = (e) => {

                    // 鼠标按下，计算当前元素距离可视区的距离

                    const disX = e.clientX - dialogHeaderEl.offsetLeft;

                    const disY = e.clientY - dialogHeaderEl.offsetTop;

                    // 获取到的值带px 正则匹配替换

                    let styL, styT;

                    // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px

                    if (sty.left.includes('%')) {

                        styL = +document.body.clientWidth * (+sty.left.replace(/\%/g, '') / 100);

                        styT = +document.body.clientHeight * (+sty.top.replace(/\%/g, '') / 100);

                    } else {

                        styL = +sty.left.replace(/\px/g, '');

                        styT = +sty.top.replace(/\px/g, '');

                    };

                    document.onmousemove = function (e) {

                        // 通过事件委托，计算移动的距离

                        const l = e.clientX - disX;

                        const t = e.clientY - disY;

                        // 移动当前元素 

                        dragDom.style.left = `${l + styL}px`;

                        dragDom.style.top = `${t + styT}px`;

                        //将此时的位置传出去

                        //binding.value({x:e.pageX,y:e.pageY})

                    };

                    document.onmouseup = function (e) {

                        document.onmousemove = null;

                        document.onmouseup = null;

                    };

                }

                dialogHeaderEl.onmousedown = moveDown;

                //双击头部全屏效果

                dialogHeaderEl.ondblclick = (e) => {

                    if (isFullScreen == false) {

                        nowHight = dragDom.clientHeight;

                        nowWidth = dragDom.clientWidth;

                        nowMarginTop = dragDom.style.marginTop;

                        dragDom.style.left = 0;

                        dragDom.style.top = 0;

                        dragDom.style.height = "100VH";

                        dragDom.style.width = "100VW";

                        dragDom.style.marginTop = 0;

                        isFullScreen = true;

                        dialogHeaderEl.style.cursor = 'initial';

                        dialogHeaderEl.onmousedown = null;

                    } else {

                        dragDom.style.height = "auto";

                        dragDom.style.width = nowWidth + 'px';

                        dragDom.style.marginTop = nowMarginTop;

                        isFullScreen = false;

                        dialogHeaderEl.style.cursor = 'move';

                        dialogHeaderEl.onmousedown = moveDown;

                    }

                }

                dragDom.onmousemove = function (e) {

                    let moveE = e;

                    if (e.clientX > dragDom.offsetLeft + dragDom.clientWidth - 10 || dragDom.offsetLeft + 10 > e.clientX) {

                        dragDom.style.cursor = 'w-resize';

                    } else if (el.scrollTop + e.clientY > dragDom.offsetTop + dragDom.clientHeight - 10) {

                        dragDom.style.cursor = 's-resize';

                    } else {

                        dragDom.style.cursor = 'default';

                        dragDom.onmousedown = null;

                    }

                    dragDom.onmousedown = (e) => {

                        const clientX = e.clientX;

                        const clientY = e.clientY;

                        let elW = dragDom.clientWidth;

                        let elH = dragDom.clientHeight;

                        let EloffsetLeft = dragDom.offsetLeft;

                        let EloffsetTop = dragDom.offsetTop;

                        dragDom.style.userSelect = 'none';

                        let ELscrollTop = el.scrollTop;

                        //判断点击的位置是不是为头部

                        if (clientX > EloffsetLeft && clientX < EloffsetLeft + elW && clientY > EloffsetTop && clientY < EloffsetTop + 100) {

                            //如果是头部在此就不做任何动作，以上有绑定dialogHeaderEl.onmousedown = moveDown;

                        } else {

                            document.onmousemove = function (e) {

                                e.preventDefault(); // 移动时禁用默认事件

                                //左侧鼠标拖拽位置

                                if (clientX > EloffsetLeft && clientX < EloffsetLeft + 10) {

                                    //往左拖拽

                                    if (clientX > e.clientX) {

                                        dragDom.style.width = elW + (clientX - e.clientX) * 2 + 'px';

                                    }

                                    //往右拖拽

                                    if (clientX < e.clientX) {

                                        if (dragDom.clientWidth < minWidth) {

                                        } else {

                                            dragDom.style.width = elW - (e.clientX - clientX) * 2 + 'px';

                                        }

                                    }

                                }

                                //右侧鼠标拖拽位置

                                if (clientX > EloffsetLeft + elW - 10 && clientX < EloffsetLeft + elW) {

                                    //往左拖拽

                                    if (clientX > e.clientX) {

                                        if (dragDom.clientWidth < minWidth) {

                                        } else {

                                            dragDom.style.width = elW - (clientX - e.clientX) * 2 + 'px';

                                        }

                                    }

                                    //往右拖拽

                                    if (clientX < e.clientX) {

                                        dragDom.style.width = elW + (e.clientX - clientX) * 2 + 'px';

                                    }

                                }

                                //底部鼠标拖拽位置

                                if (ELscrollTop + clientY > EloffsetTop + elH - 20 && ELscrollTop + clientY < EloffsetTop + elH) {

                                    //往上拖拽

                                    if (clientY > e.clientY) {

                                        if (dragDom.clientHeight < minHeight) {

                                        } else {

                                            dragDom.style.height = elH - (clientY - e.clientY) * 2 + 'px';

                                        }

                                    }

                                    //往下拖拽

                                    if (clientY < e.clientY) {

                                        dragDom.style.height = elH + (e.clientY - clientY) * 2 + 'px';

                                    }

                                }

                            };

                            //拉伸结束

                            document.onmouseup = function (e) {

                                document.onmousemove = null;

                                document.onmouseup = null;

                            };

                        }

                    }

                }

            }
        })
    }
}
